Online service providers such as web search providers, recommendation engines, social networks, and e-commerce businesses may gather data about activities (e.g., click logs, search histories, and browsing histories) and personal information (e.g., location information, demographic/socio-economic information, etc.) of users. The availability of such data enables the service providers to personalize services to individual users and also to learn how to enhance services for all users (e.g., improved search results). User data is also important to the service providers for optimizing revenues via better targeted advertising, extended user engagement and popularity, and even the selling of user data to third party companies. Permissions for sharing the user data with third parties are typically obtained via broad consent agreements that request user permission to share their data through system dialogs or via complex Terms of Service.